# The following major new features were added:* Improved Windows 8 support, in particular many 3D-related fixes* GUI: VM groups * GUI: expert mode for wizards* GUI: allow to alter some settings during runtime* Support for up to 36 network cards, in combination with an ICH9 chipset configuration * Resource control: added support for limiting network IO bandwidth; see Section 6.9, “Limiting bandwidth for network I/O”* Added possibility to start VMs during system boot on Linux, OS X and Solaris; see Section 9.24, “Starting virtual machines during system boot” * Added experimental support for Drag'n'drop from the host to Linux guests. Support for more guests and for guest-to-host is planned. * Added support for parallel port passthrough on Windows hosts* Enhanced API for controlling the guest; please see the SDK reference and API documentation for more information# In addition, the following items were fixed and/or added:* Mac OS X hosts: sign application and installer to avoid warnings on Mountain Lion* VMM: improved VM context switch performance for Intel CPUs using nested paging* VMM: added support for FlushByASID features of AMD CPUs (Bulldozer and newer)* VMM: fixed unreal mode handling on older CPUs with VT-x (gPXE, Solaris 7/8/9; bug #9941)* VMM: fixed MP tables fixes for I/O APIC interrupt routing relevant for ancient SMP guests (e.g. old OS/2 releases)* VMM: support recent VIA CPUs * GUI: network operations manager* GUI: allow taking screenshots of the current VM window content * GUI: allow automatically sorting of the VM list* GUI: allow starting of headless VMs from the GUI* GUI: allow reset, shutdown and poweroff from the Manager window* GUI: allow to globally limit the maximum screen resolution for guests* GUI: show the full medium part on hovering the list of recently used ISO images* GUI: do not create additional folders when a new machine has a separator character in its name * GUI: don't crash on terminate if the settings dialog is still open * Snapshots: fixed a crash when restoring an old snapshot when powering off a VM * Settings: sanitise the name of VM folders and settings file * Settings: allow to store the iSCSI initiator secret encrypted* E1000: 802.1q VLAN support * Storage: implemented burning of audio CDs in passthrough mode* Storage: implemented support for discarding unused image blocks through TRIM for SATA and IDE and UNMAP for SCSI when using VDI images* Storage: added support for QED images* Storage: added support for QCOW (full support for v1 and readonly support for v2 images)* Storage: added readonly support for VHDX images* Solaris additions: added support for X.org Server 1.11 and 1.12* Windows hosts: no need to recreate host-only adapters after a VirtualBox update* Windows hosts: updated toolchain; make the source code compatible to VC 2010 and enable some security-related compiler options* NAT: improvements for the built-in TFTP server